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Let's get more confused..
When the Victor supplies power to the motor from a standstill, the motor uses the torque, a function of the current flowing in what is mostly a resistor, to start turning. I = Vsupply / "R"
As soon as it starts turning, the motor becomes a generator, and generates a "back" voltage which opposes the current, by having the positive voltage generated by the armature closest to the positive supply from the Victor. The amount of current that can now flow in the "resistor" is (Vsupply - Vback)/"R".
The faster the armature spins, the greater the back voltage, and the less the current. This is why max speed can only occur at zero torque. Add some torque load, and the motor must slow down, until the back emf is low enough to allow enough current to flow to generate enough torque to turn the load. Think about how this will find an equilibrium.
When you grab the shaft and stop it, you reduce the back emf, and you are back to the locked rotor situation, treating the motor as a resistor. To measure the torque at speed (to include the effect of the back voltage), you would have to apply a brake, varying the friction on the spinning shaft, and see what load the brake will just pull with out turning, while slipping around the shaft.
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